The invention relates to a surgical retractor fixing device, comprising: (a) a clamp body arranged for removably fixing the surgical retractor fixing device to a frameset that extends along a frameset longitudinal axis and that is arranged to be mounted to an operating table, (b) a rotating body attached to the clamp body, (c) the rotating body being pivotable around an axis of rotation, (d) the rotating body comprising a fixing element arranged for fixing a surgical retractor. According to a second aspect, the invention relates to a method of retracting structures in a surgical situation.
Originally, surgical retractors were limited to hand-held instruments with multiple curved fingers used to hold open incisions during surgical procedures. The surgeon or an assistant would hook the fingers of the surgical retractor over the edge of an incision and apply tension to hold the incision open to provide access for the surgeon to internal bodily structures.
In approximately the last two decades, surgical retractors have been developed that are secured to a surgical table or other structure to allow retraction to be accomplished without the necessity of the surgeon or an assistant constantly holding the retractor.
In general, a table rail post is the foundation of a surgical retractor system. It provides an anchor for a frameset and other hardware onto which retractor instruments and other surgical instruments may be attached. A variety of retractor instruments with variably shaped retractor fingers are used in surgery to assist the surgeon in holding a surgical incision open or to move anatomical structures out of the way. Generally, currently available surgical retractor systems use cam mechanisms or occasionally screw clamps to lock various members of the retractor system in position.
Currently available surgical retractor systems generally include round stock retractor systems and flat stock retractor systems. Flat stock retractor systems suffer the limitation that because of the rectilinear nature of the various components, the components must be joined at substantially right angles in order to interconnect. Thus, the number of orientations in which flat stock retractor systems can be assembled is limited.
Round stock retractor systems generally are preferred because they allow for the interconnection of the various retractor system components at a variety of different angles because of the ability of the round stock parts of the system to rotate relative to one another and to clamp components.
Round stock retractor systems include various rod shaped parts that, initially, were connected together by screw-threaded type clamps. As screw-threaded type clamps were used, it was discovered that there was a tendency for the screw clamps to deform the cylindrical members of the retractor system. In addition, the threads of the threaded clamps would tend to wear and fail. Further, setting up, positioning and interconnecting the parts of the retractor system often required both hands, or possibly both hands of one individual, plus an assistant to assemble the system. Over time, there has been a shift from screw-clamp connection systems to cam lock or over center lock connection Systems.
Cam lock systems generally include two interconnected clamps that are configured to grip the rod shape retractor system members and that can be adjusted in rotation relative to each other. One rod shaped component is gripped in each clamp. The two interconnected clamps are activated by some sort of actuator such as a lever which then locks the two clamps to two rod-shaped members and also simultaneously locks the two clamps relative to each other in rotation. One disadvantage of this arrangement is that when the clamps are released, they are released completely from both rod-shaped members as well as in relative rotation, requiring that the retractor system be completely repositioned and realigned before reclamping.
Surgical retractor systems are used to manipulate living tissue. Living tissue can be damaged by the application of pressure to the living tissue for too long a time. Therefore, it is recommended that during surgical procedures where mechanical retractors are used, periodically the retractors should be loosened or tension should be lessened on the retractors to allow increased blood flow to the tissue being retracted to prevent tissue hypoxia and possible necrosis, This requirement, along with the limitation of current retractor Systems, creates a dilemma for the surgical team. The surgical teams can disconnect the surgical retraction system periodically but then be required to make complete adjustments of each surgical retractor to reconnect it. Alternately, the surgical team can leave the living tissue retracted under tension for long periods of time and risk tissue damage or necrosis to the tissues being retracted. Surgical team members tend to be reluctant to disconnect and then readjust the retractor system if the readjustment is time consuming or unwieldy or if readjustment will alter the carefully positioned relationship of anatomical structures.
Another issue that arises with current round stock surgical retractor Systems arises from the fact that surgeons generally prefer to locate retractors so that they are providing retractive tension at an angle. Surgeons prefer this approach in order to move the retractor to one side of the field in which they must work so that the retractor does not interfere with their movements. When the surgical retractors are offset, quite often it is impossible to position the retractors so that the retractor is pulling completely linearly with relation to the long axis of the rod-shaped members. This imparts a torsional or rotational force to the clamps that are secured to cylindrical or rod shaped members of the retraction system. This force tends to cause the clamps of the retraction system to slip about the rods in a rotational fashion. A common response to this problem is to increasingly tighten the clamp that is applied to the rod-shaped member. Unfortunately, when tightened beyond a certain point, the clamp will tend to create deformation or galling of the rod shaped member to which it is clamped making it more difficult to adjust the system for future usage.
Another problem that arises with currently available retraction systems is that when a retractor is fixed to the system by a current clamp the joint created between components is completely locked so that the components joined are immovably fixed in all axes. Commonly, it is necessary for the surgeon or an assistant to increase or readjust retractions for certain activities. Adjusting retractions means that the surgeon or an assistant must loosen the clamp holding the retractor, reposition the retractor, and then reapply the clamp. Since the prior art clamp releases completely from two rods and in rotation simultaneously, at least two hands are required to realign and retighten the system. This can be quite awkward as there is a period of time where tension on the retractor is reduced and tissues may move in an undesirable fashion when the tension is reduced.
It is the technical problem of the present invention to mitigate at least some of the above mentioned disadvantages.
The present invention solves the problem with a surgical retractor fixing device having the features of claim 1. According to a second aspect, the invention solves the problem with a method of retracting structures in a surgical situation, the method comprising the steps: (i) mounting an anchor element to an operating table, a frameset being attached to the anchor element, (ii) attaching a surgical retractor according to the inventions to the frameset, (iii) arranging a surgical retractor relative to a human or animal patient, (iv) fixing the surgical retractor fixing device to the frameset, and (v) moving the surgical retractor, such that it retracts tissue of a patient.
The surgical retractor assembly of the present invention is arranged to be anchored to a surgical table rail or operating table, to allow retraction of anatomical structures. The surgical retractor system generally includes a retractor that can be secured in a rotating body that is further secured to a clamp body portion that, in turn, can be secured to the frameset, framing arm or other structure that, in turn can be secured to the operating table via an anchor element.
The retractor of the present invention, in one aspect of the invention, is generally conventional in structure, including curved retractor fingers secured to a shaft. The shaft may have a larger diameter portion and a smaller diameter portion.
The rotating body is rotatably securable to the clamp body.
In one embodiment of the invention, the rotating body is generally cylindrical in structure and is capable of rotation a total of about 120 degrees or even 180 degrees. The rotating body encloses or supports a fixing element arranged for fixing the surgical retractor. The fixing element may include a bind plate that is pivotally secured at one end. The bind plate includes a bind aperture which is sized to be slightly larger than the large diameter portion of the retractor. In addition, the rotating body has openings approximately aligned with the bind aperture that allow passage of the large diameter portion of the retractor through the rotating body. The bind plate is pivotable from a free-movement position where the bind plate is at a less acute angle to the shaft of the retractor to a locking position where the bind plate is pivoted to be at a more acute angle to the shaft of the retractor and thus binds the shaft of the retractor in the bind aperture preventing it from moving in one direction. Thus the retractor shaft is secured by the bind plate so that it can be withdrawn in a first direction to increase retraction but will automatically frictionally lock when moved in an opposing second direction to resist tension on the retractor.
The rotating body may include a release element such as a release button which is operably coupled to the bind plate and allows an operator to press the release button to transition the bind plate from its acute angled engagement with the shaft of the retractor to the free-movement position. Thus, retraction force can be adjusted without the necessity to release any of the other structures in the surgical retraction system. The release button may be biased toward the locked position of the bind plate by a spring or other biasing member. This arrangement ensures that a biasing force will be constantly applied to the bind plate so that the bind plate does not inadvertently slip.
The clamp body of the present invention generally includes a flex jaw and a fixed jaw and a rotating body receiver. The clamp body portion may be a substantially unitary structure that may be formed out of metal or another rigid material. In addition the clamp body may be formed out of several pieces of material such as a stainless steel. The clamp body defines a first cylindrical bore and a second cylindrical bore that are sized to receive a first and second piston therein. The first cylindrical bore and a second cylindrical bore may be substantially coaxially oriented in one aspect of the invention. The first cylindrical bore is in communication with the flex jaw portion of the clamp so that a first piston, located therein, will bear upon the flex jaw. The second cylindrical bore is in communication with a rotating body cavity within the body which is dimensioned to receive the rotating body. In one aspect of the invention, the rotating body includes a groove about the external perimeter thereof so that the second piston may bear against this groove. In one embodiment, the groove is of an appropriate circumferential length to allow the rotating body to pivot around an axis of rotation, the rotating body being pivotable having a pivotable angle range of 0 to 230 degrees. It may even be advantageous to limit the pivot angle range to 0 degree to 180 degree. In this case, the retractor is prevented from being inserted into the rotating body from the wrong side.
The rotating body may include a crescent-shaped extension extending from a bottom thereof that can be received into the rotating body cavity. In this embodiment, the second piston is sized to reach across the rotating body cavity and to bear against the concave side of the crescent extension. The body of the clamp body portion also defines a cam support cavity. The cam support cavity has a small diameter portion and a large diameter portion. The cam support cavity is in communication with both the first and second cylinder bores. In one embodiment of the invention the cam support cavity is substantially perpendicular to the first and second cylinder bores.
The present invention may also include a cam mechanism. The cam mechanism generally includes a handle such as a locking lever and a cam shaft. The handle may be pivotably mounted to the cam shaft to allow the handle to move from a position that is generally parallel to the cam shaft to a position generally at right angles to the cam shaft. The handle may also be fixedly mounted orthogonal to the cam shaft. In either case, the handle is located or locatable so as to be generally perpendicular to a rotational axis of the cam shaft.
The cam shaft generally includes a small axle portion, a dual cam, a larger axle portion, and a partial cone portion. The small axle portion is dimensioned to be rotatably received in the small diameter portion of the cam support cavity. The large axle portion is dimensioned to be received into the large diameter portion of the cam support cavity.
The dual cam portion generally includes a first cam lobe and a second cam lobe that may be located approximately 180 degrees apart. The dual cam portion may include a differential cam wherein the lobe of one cam may have a higher lift than the lobe of the other cam.
When the cam mechanism is inserted into the cam support cavity, the lobes of the two cams of the dual cam each bear upon one of the first and second pistons. In one aspect of the invention, rotation of the cam mechanism causes the lobes of the cams to force the two pistons in opposite directions. The first piston bears against the flex jaw of the clamp portion and when the piston is advanced, causes the flex jaw to move toward the fixed jaw, thus providing a clamping force that can secure the clamp to cylindrical structure of a surgical rail system.
The second piston is moved toward the rotating body. Depending upon the embodiment of the rotating body, the piston may bear against the circumferential groove, or the concave side of the crescent extension. Force applied to the second piston forces the rotating body against the interior of the rotating body cavity, thus frictionally locking the rotating body in a particular orientation when the cam mechanism is operated.
Thus, when the cam mechanism is operated, it simultaneously secures the clamp portion to a cylindrical structure of a surgical retractor support and locks the rotating body in a particular rotational orientation relative to the body of the clamp body portion. It is notable that adjustment of the retractor relative to the rotating body is independent of the operation of the cam mechanism.
According to an alternative embodiment, the clamp body may have a mouth for at least partially encompassing the frame set, the mouth being open in a mouth direction, and the clamp body comprising a locking device, the locking device having a locking rod arranged for engaging with the frameset thus fixing the clamp body to the frameset and a locking lever arranged for actuating the locking rod, the locking lever being pivotable around a locking lever swivel axis, the locking lever swivel axis being substantially perpendicular to the frameset longitudinal axis and to the mouth direction. This yields the advantage that a surgeon may first adjust and fix the surgical retractor concerning its direction relative to the frameset an afterwards fixing into the frameset.
When the retractor is inserted into the rotating body through the retractor openings and through the bind aperture of the bind plate, the spring located within the rotating body biases the bind plate to an acute angled locking orientation relative to the retractor shaft Thus, the retractor will be easily movable in a first direction relative to the rotating body and locked or jammed in motion in an opposing direction. In this way, the retractor can be withdrawn away from the patient to apply retraction force. Retraction force can be easily increased by pulling the retractor farther into the rotating body. In addition, retraction force may be reduced by pressing the push button release, thus moving the bind plate to an orientation generally perpendicular to the retractor shaft and allowing the retractor shaft to be moved in either direction as required. Release of the release button immediately locks the retractor shaft with relation to the rotating body.